/* Copyright 2015 Bloomberg Finance L.P.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import * as d3Scale from 'd3-scale';
import { Scale } from './Scale';

export class LinearScale extends Scale {

    render() {
        this.scale = d3Scale.scaleLinear();
        if(this.model.domain.length > 0)
            this.scale.domain(this.model.domain);
        this.offset = 0;
        this.create_event_listeners();
    }

    expand_domain(old_range, new_range) {
        // If you have a current range and then a new range and want to
        // expand the domain to expand to the new range but keep it
        // consistent with the previous one, this is the function you use.

        // The following code is required to make a copy of the actual
        // state of the scale. Referring to the model domain and then
        // setting the range to be the old range in case it is not.
        const unpadded_scale = this.scale.copy();

        // To handle the case for a clamped scale for which we have to
        // expand the domain, the copy should be unclamped.
        unpadded_scale.clamp(false);
        if (this.model.domain.length) {
            unpadded_scale.domain(this.model.domain);
        } else {
            // if the domain is empty, it will lead to NaN/NaN
            console.error('No domain exists for scale, is that any data associated with this scale?')
        }
        unpadded_scale.range(old_range);
        this.scale.domain(new_range.map(function(limit) {
            return unpadded_scale.invert(limit);
        }));
    }

    invert(pixel): number {
        return this.scale.invert(pixel);
    }

    invert_range(pixels) {
        //Pixels is a non-decreasing array of pixel values
        return pixels.map((pix) => this.invert(pix));
    }
}

